The French in Denial

It could happen to anyone. This time it happened to be a French airplane with French pilots flying for a French airline.

For two years the “black boxes” (the voice recorder and the DFDR) lay in peace on the floor of the Atlantic Ocean, 13, 000 feet below the waves. For two years there was conjecture, speculation, and (some quite fine) attempts at reconstruction. Then the black boxes surfaced, along with other hard evidence, including the jackscrew from the Trimmable Horizontal Stabilizer.

For months as the Bureau d'Enquêtes et d'Analyses slowly released information, we (and the BEA) put together the tragic and terrifying story. But the story stopped abruptly, the last chapter removed or never written.

Now a French aviation writer, Jean-Pierre Otelli, has published that last chapter independently of Air France, Airbus Industrie, and The BEA. The story ends as we knew it would – badly and sadly – but now we have more grisly detail and less room for denial.

The Bureau d'Enquêtes et d'Analyses is incensed. In a press release on October 13, 2011, (look under News in the sidebar) they claim that the transcription released by Otelli “mentions personal conversations between the crew members that have no bearing on the event, which shows a lack of respect for the memory of the late crew members” (my emphasis). The same day the London Telegraph published an account of the final minutes. The account seems to have been shortened since October 13, and I have been unable to find the original. Those who are interested may add the following after “According to an official report released earlier this year, the last words were from Captain Dubois who said: 'Ten degrees pitch.'”:

But in his new book Mr Otelli asks who will be held responsible 'for this mess'. 'Is it a training problem, fatigue, lack of sleep, or is it due to the fact the pilots are confident that an Airbus can make up for all errors?,' he writes. France's air accident investigation unit, the BEA, reacted angrily to the publication of the book, with a spokesman saying printing the conversation showed a 'lack of respect to the memory of the crew who died'. Air France has denied that its pilots were incompetent, but has since improved training, concentrating on how to fly a plane manually when there is a stall. Both Air France and Airbus are facing manslaughter charges, with a judicial investigation led by Paris judges already under way. A judge has already ordered Air France to pay some £120,000 in compensation to the families of each victim, but this is just a provisional figure which is likely to multiply many times over. THE FINAL MOMENTS Marc Dubois (captain): 'Get your wings horizontal.' David Robert (pilot): 'Level your wings. 'Pierre-Cedric Bonin (pilot): 'That's what I'm trying to do... What the... how is it we are going down like this?'Robert: 'See what you can do with the commands up there, the primaries and so on…Climb climb, climb, climb. 'Bonin: 'But I have been pulling back on the stick all the way for a while. 'Dubois: 'No,no, no, don't climb. 'Robert: 'Ok give me control, give me control.'Dubois: 'Watch out you are pulling up. 'Robert: 'Am I?'Bonin: 'Well you should, we are at 4,000.'As they approach the water, the on-board computer is heard to announce: 'Sink rate. Pull up, pull up, pull up. 'To which Captain Dubois reacts with the words: 'Go on: pull.'Bonin: 'We're pulling, pulling, pulling, pulling.'The crew never discuss the possibility that they are about to crash, instead concentrating on trying to right the plane throughout the final four minutes. Dubois: 'Ten degrees pitch. 'Robert: 'Go back up!…Go back up!…Go back up!… Go back up! 'Bonin: 'But I’ve been going down at maximum level for a while.'Dubois: 'No, No, No!… Don’t go up !… No, No! 'Bonin: 'Go down, then!'Robert: 'Damn it! We’re going to crash. It can’t be true!'Bonin: 'But what’s happening?!'The recording stops.

What we know, briefly, is this: Air France 447 ventured into a line of thunderstorms along the InterTropical Convergence Zone. Four other flights diverted around the storms. In the zone the flight encountered unusually warm temperatures and supercooled water droplets – enough to briefly overwhelm the heaters in all three pitot tubes, denying airspeed information to the Flight Control Computers for long enough to cause them to kick off the autopilot and to degrade the flight controls from Normal Law to Roll Direct/Pitch Alternate Law. Despite the fact that by the book they were too heavy to climb, the pilot flying (First Officer David Robert) zoomed up from 35,000 feet to almost 38,000 feet, dissipating the aircraft's energy and exposing it to coffin corner, where Mach buffet meets stalling speed. With brief lapses he held back pressure on the sidestick for the remainder of the flight.

First the airplane stalled (quit flying because the Angle of Attack was too great). Then, because of the steady back pressure on the sidestick, the autotrim wound the Trimmable Horizontal Stabilizer (more powerful than the elevators) to full nose up. (The THS jackscrew was found in this full nose up condition). By now the aircraft was in a deep stall, falling almost straight down in a near-level attitude.

There is plenty of room for argument about why it happened this way. Many (including David Learmount at Flight Global and myself) have started that discussion. It must continue, because we must know not only why F/O Robert stalled the aircraft, but much more importantly why he didn't know he had stalled it, why he had a totally inaccurate picture of what was happening, and why there was a complete absence of situational awareness on that Flight Deck.

It may look as if I am placing blame solely on F/O Robert. Absolutely not. That would be much too easy. I and others have already written many pages (see AF447 on my blog) trying to piece together all the factors at work in this accident. We will write many more.

As in all accidents, there is a chain of events and decisions which gradually (at first!) reduce maneuvering room. The first of these was Captain Dubois' decision to take crew rest approaching the ITCZ.

But before that came Air France's decision to carry less fuel than the spirit of the regulations requires, by filing the Flight Plan as Rio to Bordeaux, alternate Paris. Even earlier, the brilliant (I am not being ironic or facetious, I admire the man) Bernard Ziegler designed the Airbus to be “pilot-proof” and impossible to stall. However he (or his designers) also left the autotrim functional in Pitch Alternate Law, an oversight I believe should be corrected ASAP. Finally, (and earliest of all) you and I and everyone else who has traveled since Airline Deregulation in 1978 believes or wants to believe in cheap seats.

It could happen to anyone.

Sadly, it has all been foreseen. Recently I read an article which bluntly calls out the forces that led to this accident. It is called The Training Paradox, and was written by pilot, engineer, and lawyer Mark. H. Goodrich. Some of the accidents and incidents he describes stood my hair on end. Unfortunately I cannot provide a link to it. I read it in Position Report, November 2011, Volume VIII Number 3. (This is the magazine of the Retired Airline Pilots of Canada).

The very experienced and knowledgeable Mr. Goodrich shows how the forces of deregulation have derailed traditional career paths and interrupted the passing along of knowledge. As a result, the craft, the trade, the profession if you will of flying is dying a slow death. Neither are regulatory bodies or airline management immune from this decay.

This time it was the French. It is not surprising they are in denial. But it could happen to anyone, and it will.


Treasure in Tragedy: AF 447

The treasure in the tragedy of AF 447 is what it can teach us.

Thank you, David Learmount at Flight Global, for calling for dialogue. Thank you Wood's Hole Oceanographic Institution and Bureau d’Enquêtes et d’Analyses for recovering data we can all work from.

Thank you, David, for offering to share the blame. All of us share the blame, all the way down to the passenger who wants a cheaper flight. But in the end, blame is irrelevant. Blame only serves economic interests which demand simple answers. These answers will not be simple.

Let us all be brave and try to speak truth as we see it. Let us all bring our training and experience to bear on the recovered data and mine it for lessons and solutions.

AF447 Transcript

David Learmount’s article today reveals two key weaknesses: one in the crew and the other in the aircraft.

The crew had not clearly declared who was flying the aircraft – in airline lingo who was PF and who was PNF.

Airbus sidesticks add algebraically. When the aircraft hit the water the left sidestick had some nose-down input and the right sidestick was at full nose-up. The Trimmable Horizonal Stabilizer (the horizontal tail) was already at full nose-up, most likely because of continuous nose-up sidestick applied while in Alternate Law.


Your Roof is Gonna Leak . . .


I am a pilot. I am lucky to have retired without incident from a career at an airline. Flying is still in my bones.

Mine is an apprenticeship trade. You can’t learn it in a classroom or by reading a book, although both help. You have to get your hands on an airplane.

Most trades are like mine. It takes constant study to stay current in the field. The reference books, software, and reams of data relevant to the job are huge and growing. But the essential learning, the learning that serves as backbone and basis for all the stuff in the reference books, is hands-on experience taught by a mentor and teacher. In turn you should pass this knowledge on to the next generation.

Tradespeople are no better and no worse than others. The majority of them like going to work and doing the the best job they can. There is satisfaction in building something or in accomplishing a mission. You can look back and say, I built that, or I did that.

But like rule of law or paying taxes, plying a trade with skill and devotion is a social contract. Protect me from lawbreakers, ensure others pay their fair share. Give me a living wage so I can support a family, and respect my work for what it is.

Nor are we tradespeople to be divided from business people, put in a separate category. On the contrary most small businesses are founded and powered by tradespeople, be they plumbers, machinists or software engineers with ideas. Entrepreneurship and the trades are interdependent and have been since the days of the guilds. Perhaps what we are less compatible with is management.


I was lucky also to have spent most of a decade flying and teaching on Airbus aircraft. The design of the A320 is revolutionary, extraordinary, and even beautiful. She never failed to delight me (like mariners, I thought of my ship as a person, a female) and she remains one of the loves of my life.

But she is not perfect. Call it my fallacy of anthropomorphism if you will, but I believe that a man-made object cannot be more perfect that the sum of its creators. It can be outstanding, it can be beautiful, but it cannot be perfect. Lovely as she is, my Airbus is no exception. She has her faults.

Her qualities have been called to review by two recent events with very different outcomes: Chesley Sullenberger's heroic handling of a ditching in the Hudson River, and the crash of an A330 in the Atlantic Ocean with the loss of all on board.

All airplanes have what is called an envelope. Fly faster than Va (maneuvering speed) and turbulence or rough handling can result in damage to the airframe. Fly slower than Vs (stall) and the wing can no longer generate enough lift to hold the airplane up. Fly faster than Vd (dive speed) and all manner of bad things can happen, from Mach tuck to control flutter to loss of control. The technicalities of the flight envelope can fill a book and have, many times over. The parameters include aircraft weight, air density (altitude, temperature) and G loading. But the bottom line is that it is the pilot's responsibility to keep the airplane in the envelope, to fly it as it was designed to be flown.

Bernard Ziegler had a different idea.

He was my love's Daddy. You see him in her everywhere you look. She is beautiful, intelligent, accomplished, and refined. She is uncompromising. She is very French.

She has an envelope like any other airplane. She flies with the same aerodynamics as they do. But her Daddy added a new feature to her design: envelope protection.

With the A320 and subsequent models, the pilot cannot “push the envelope”. He can push or pull as much as he wants and she will go to the edge, but not over the cliff. She is impossible to stall.

As long as she is in NORMAL LAW.

Her fly-by-wire control system is impressive in the extreme. There have been no known failures in service. But like us she depends on sensors, eyes and ears. And of course electricity to power her hundreds of computers. Starve her, blind her, or deafen her and you are asking for trouble. Chesley Sullenberger understood her. His first act was to reach up and start the Auxiliary Power Unit. This one strategic move kept power on the aircraft busses as Jeffrey Skiles, the First Officer, went through the engine restart drills. This one strategic move kept her in Normal Law until touchdown.

AF447 was approaching the Intertropical Convergence Zone, the ITCZ, the doldrums. It was night and as usual there was a long line of thunderstorms in the Zone, crossing their track obliquely. The Captain had just left the Flight Deck for his planned rest. The most junior pilot – the relief pilot – was in the left seat flying the aircraft.

Ahead of them a small storm was showing on the radar. Despite its size it was dense enough to reflect all of the energy from their radar. The result – a well-documented phenomenon called attenuation or blanking – was that a gap appeared in the line behind the small storm. AF447 flew around the corner and suddenly the gap was gone. They were plowing into the main line of thunderstorms.

Supercooled water is unusual at FL350 but not unusual in thunderstorms. Drops of supercooled water freeze instantly when disturbed – as for example by a fast-moving aircraft. The temperature that night was an unusually warm minus 40 C., just warm enough to keep the drops from freezing and cold enough so the heating elements in the A330's pitot probes were not powerful enough to keep the probes open. All three pitots were temporarily blocked, cutting off all airspeed information.

She was blind and deaf. Panicked, she shut down her envelope protection and called out to her pilots for help, shutting down the autopilot and autothrust and reverting to Pitch Alternate Roll Direct Law. Visual and aural warnings cascaded across the ECAM and into the speakers. Beautifully designed and prioritized for foreseeable failures, the warnings that night became a powerful distraction, demanding the pilots' attention at just the moment they needed to ignore her.

She was squealing like a stuck pig. If the pilots could have read her right that night, what they would have heard was, I'm gone, guys. I'm outta here. You have control.

Blind, deaf, and still squealing, the A330 handed control to the relief pilot. He pulled back on the sidestick. She zoomed upwards, climbing to FL380 at 7000 feet per minute, rapidly losing energy, her angle of attack increasing toward the stall. In Pitch Alternate Roll Direct Law the pilot's back pressure on the sidestick was also moving the powerful Trimmable Horizontal Stabilizer, moving it slowly to full nose-up, effectively locking them into the stall that would follow momentarily.

Today David Learmount of Flight Global posted a blog titled Being an airline pilot isA profession in decline”. Is it really? He quotes from William Langewiesche's book Fly by Wire, citing Langewiesche's admiration for Bernard Ziegler and the Airbus and his ambivalent attitude toward airline pilots. I will add another quote from the book:

“What did Ziegler want? He wanted to build an airplane that could not be stalled – not once, not ever – by any pilot at the controls.”

She fell flat, nose and wings level with the horizon, falling not flying, her angle of attack near ninety degrees, her rate of descent 10,000 feet per minute. Four minutes later she hit the water.

Nemesis and Lesson

Here is another quote from Fly by Wire:

“If you design airplanes for (airline pilots) to fly, you must grapple with not only with the existence of a few who are incompetent from the start, but also with the fact that plenty of once-excellent pilots grow unsafe with time. They become arrogant, bored, or complacent. They drink, they fade, they erode.”

Bernard Ziegler is (was) a brilliant test pilot and engineer. (Like me, he is getting older.) He knew that he was on the far right flare of the bell curve. He knew (as do we all) some examples from the left rim of the bell.

I am from somewhere in the middle of the curve. I was lucky, worked hard to maintain my competence, and survived my job. I don't dispute the factuality of the above quote. But I would add a caution:

Underestimate a tradesperson at your own risk.

Chesley Sullenberger knew his airplane, respected her and treated her like an equal. He expected Jeffrey Skiles to act professionally and he did. He was proud of his profession, his trade. That was his true achievement. The successful ditching followed from it, a corollary.

David P. Davies gets it right-way-around in his classic Handling the Big Jets:

“Airline flying is just money for old rope most of the time . . .”

He recognizes, as pilots say, that flying is hours of boredom punctuated by moments of sheer terror.

But he also points out the need for training of the highest quality. That designing an airplane that is capable of landing safely with half its engines failed is of no use if you haven't trained the pilots to do the maneuver. If you haven't given them the confidence that they can.

So pilots: know your airplane. Treat her and your fellow-pilots well. Expect the best from them.

And to everyone, especially homeowners: respect tradespeople. Search out those who are proud of their work. Especially if you're looking for a roofer.